Calvert Formation sperm whales

There is only one modern species of sperm whale, but it’s a family that was more diverse in the past. A big question for paleontologists is “just how diverse”, because sperm whales are rare in the fossil record. The most common remains are teeth, but unfortunately sperm whale genera cannot be reliably identified based on teeth alone.

That doesn’t mean that the teeth are completely useless for identification. The uppermost bed of the Calvert Formation includes at least two species of sperm whales, based on the types of teeth that have been found.

In the photo above, the tooth on the right is from the Rappahannock sperm whale that I’ve been writing about recently. This is from a very large whale, comparable in size to the baleen whales from the same formation.

The tooth on the left is from the same bed, but from Carmel Church. Besides the rather obvious size difference, the teeth differ in that the small one has no enamel crown. Small-toothed sperm whale skulls (generally referred to as Orycterocetus) have been found lower down in the Calvert Formation.

So, even with teeth alone, we can say definitively that there were at least two sperm whales in the upper Calvert Formation, even if we can’t be 100% sure what those two species are.

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This entry was posted in Carmel Church odontocetes, Carmel Church Quarry, Chesapeake Group, Rappahannock River sperm whale and tagged . Bookmark the permalink.

14 Responses to Calvert Formation sperm whales

  1. Doug says:

    Interesting. Reminds me of all the stuff you said about Santa Barbara’s skull. Oh, and I apparently made the news: http://www.venturacountystar.com/news/2008/jul/20/nb1fcmammoth20/

  2. Alton Dooley says:

    That’s great, Doug! Congratulations. Always good to see fossils making the news.

  3. Doug says:

    Thanks Butch! And looks like one of our sperm whales is going to be a tv star: http://www.history.com/genericContent.do?id=59506

  4. Markus says:

    Very nice to see finaly additional information about Brygmophyseter. The reconstruction looks nice, but I have several doubts about it. The fin on the back for example looks too small, as well es the flippers, keeping in mind that this guys had to be both fast and manoeuvrous. The eye-patch like those seen in orcas don´t really fit with the rest of the concept, because there should not be too much artistic parallels with modern killer whales. The tail fin looks to long but the actual tail a bit thin. Furthermore the ventral keel seen in modern sperm whales was probable a comparably modern development, as even pygmy sperm whales and their relatives show not ventral keel. Something I find also strange is the size. Was Brygmophyseter actually that big? Its articulated skeleton looks much smaller, more orca-sized.

  5. Alton Dooley says:

    Hmmm….

    Well, there are some issues with that page. Part of it is oversimplification (Brygmophyseter is not known from the entire Miocene, I believe, but only from the early Miocene). Forty feet long seems large to me too, though; I’ll have to check that. It should be about the same size as Zygophyseter.

    The deep counter-shading is probably pretty likely; it’s found in a wide variety of odontocetes that hunt near the surface. I would think the eye-patch is a reach, though, as it’s only known in killer whales.

    I wouldn’t put too much faith in soft tissue (fluke and dorsal fin) reconstructions based on inferred lifestyle. Two of the fastest-swimming and most maneuverable odontocetes are Dall’s porpoise and the right whale dolphin, which look nothing alike. Dall’s porpoise is stocky with a large dorsal fin, while the right whale dolphin is serpentine and has no dorsal fin at all. So it seems that there are multiple paths for odontocetes to attain the fast, maneuverable lifestyle.

    Incidentally, I think at least part of the Brygmophyseter forelimbs were recovered, so there should be some data on their length.

    There is some good evidence that killer whales do rely on maneuverability in hunting, at least in hunting baleen whales. There was a paper in Marine Mammal Science a couple of years ago (I don’t have it in front of me) that found that killer whales were generally unable to catch minke whales in the open ocean. But if the minkes had to turn to avoid an obstacle, the killer whales almost always caught them.

  6. Markus says:

    Thanks for your fast response Alton. I think the coloration is something about we can say nearly nothing in fossil whales, given the fact how vast the variability of colours and pattern among living whales is. If we would know orcas only from fossils, we would never suppose that they have such a striking colour-scheme, as well as the huge dorsal fin. Sperm whales and their small relatives are very conservative in their colour-scheme, so a simple dark grey or black colour with a brighter underside could be the most probable colour (or perhaps not, we´ll never know). The life-sized model of Zygophyseter in Italy looks in its colour comparably similar to moder sperm whales, but it looks really good, especially with the white areas around the mouth.
    I know, there are several ways in which a fast and maneuvrable whale can be built, but this reconstruction of Brygmophyster just looks a bit strange. The Kogia-species have still a very conservative post-cranial anatomy, without any humps or ventral ridges, so I could well imagine that the archaic sperm whales which branched very early from the family-tree of the sperm whales still had a comparably normal built, without all the strange features found in Physeter catodon.
    Some time ago I read a highly intersting old paper which wrote about the differences and similarities between the skulls of a young kogia specimen (I don´t remember which species), a young Physeter and Aulophyseter. Interestingly it seems that tha cranial modifications of the Kogia-Species are actually much higher developed than those of Physeter.
    There is also something about the looking of the archaic sperm whales what really drives me crazy. How looked their spermaceti-organ? Was it round as in this reconstruction of already high as in Kogia, Physeter and some beaked whales? I made my Zygophyseter redonstruction with a sperm whale-like spermacetii-organ, but with a free snout. It makes huge differences if you draw such a whale with a round or a high head. I have drawn a lot of possible life-reconstructions of killer-sperm whales, but I am still not sure what I should think about them. Some look false, some looks realistic.
    It would be really a big help if I would know more pictures of those skulls, especially from dorsal. I could also found nearly nothing about the other fossil sperm whales, only one dorsal view of Aulophyseter and the pictures in the paper about Zygophyseter. I have a bit time now, and I would love it to sculpt a killer-sperm whale, but there are still too much different interpretations. There is a (not very nice drawn) life-reconstruction of Hoplocetus, but it looks not right I think.
    If I would make a small model, I would give it a body with the proportions given by the skeleton and flippers and a dorsal fin similar to kogia sima, but possibly a bit bigger, and with a similar colouration but with some features of Physeter.

  7. Doug says:

    All interesting stuff. Like Alton said, oversimplification. I don’t trust their size chart, cause there is no way Gastonia was THAT big. But here is the sperm whale reconstruction I have been looking at for years: http://www.flickr.com/photos/jobaria/2701739204/

  8. Alton Dooley says:

    Don’t know what that ventral fin is…

    I’m guessing that countershading (like in killer whales) is going to be prevalent in whales that usually feed within about 50-100 m of the surface where you still get sunlight; it’s essentially camouflage so that the predator doesn’t make a silhouette when seen from below (or a bright patch from above). It’s likely that sperm whales and kogiids are uniform color because they feed so deep that no sunlight is present (also beaked whales, pilot whales). Note that this isn’t universally true; bottlenose dolphins (Tursiops) are uniformly grey, and usually feed in shallow water (although Tursiops may be the ultimate in diverse feeding styles).

    The size of the spermaceti organ is tough to get a handle on, in part because Physeter is highly specialized and quite different from all the fossil species. Bianucci and Landini made a good case that the spermaceti organ did not extend to the tip of the rostrum in Zygophyseter, but that the rostrum formed a beak somewhat like that in most dolphins. I don’t agree 100% with their reconstruction, though; I don’t like the way they have the melon overhanging in the front. I envision something more like a bottlenose whale in lateral view (but with larger jaws).

    I’m not sure if Brygmophyseter is like that. The large-toothed sperm whale from Carmel Church seems to have most of the rostrum free of the melon.

  9. Markus says:

    I think odontoceti are really extremely strange in the way of their colouration. Orcas have a striking black and white scheme, but false killer whales, which are not that different in their ecology have a simple dark greyish skin with a brighter underside, a colour scheme you would suppose for most big marine predators.
    Sperm whales and Kogia have a very simple colouration, but for some strange reason some of the beaked whales which also dive very deep, have a lot of markings on their bodies…

    To come again to the spermaceti-problem. The cranium of Zygophyseter shows for example that it had a very well-developed spermaceti organ, even if it didn´t cover the rostrum. But could it be that it possibly looked like those of some beaked whales like the northern bottlenose whale, Baird´s beaked whale or Arnoux´ beaked whale? Something I find a bit strange in Bianuci´s reconstruction is the extremely high head. Sadly the skull is broken at the posterior dorsal part, but I am not sure if it was actually as high as in the reconstruction chart of the skull in the Zygophyseter paper.

    BTW, do you know the book “Whales Dolphins and Seals: A Field Guide to the Marine Mammals of the World” by Hadoran Shirihai? It is most probably the most complete book about marine mammals, and includes nearly all species, and often even subspecies with hundreds of great pictures. Most of the whales are shown in lateral and ventral view, and in most cases there are even pictures which show the differences between males, females and sometimes even subadult specimens. It includes also a lot of very obscure species which you won´t hardly find in popular literature, like some of the beaked whales. There is comparable few background information, but the book has already nearly 400 pages, so this is really not bad.

  10. Markus says:

    You probably know it already, but if not it could be of interest for you that there are several fossil skulls of primitive sperm whales at Maryland: http://www.nmnh.si.edu/rtp/students/2006/schedule06_paleobiology_tour_photo3.html

  11. Alton Dooley says:

    Nice photos at that link, Markus.

    As you guessed, I have been there a number of times (in fact, my dissertation was based primarily on SI specimens). I’m planning to go there again this fall.

    Incidentally, the sperm whale in those photos (which, if I recall correctly, comes from a lower bed in the Calvert) is different from both the species in my photo.

  12. Alton Dooley says:

    There are still problems with Apple’s “upgrade” to their new hosting software, which is why I haven’t posted in since last week. It appears that, with my next post, all the previous reader comments will be deleted. I’m trying to avoid that, but I’m not optimistic.

    I think there will also be a url change when the update is completed. I think the new address will be:

    http://web.me.com/dooleyclan/Site_2/Blog/Blog.html

    I apologize again for the inconvenience.

  13. Alton Dooley says:

    The blog appears to be running more-or-less correctly at the new address (http://web.me.com/dooleyclan/Site_2/Blog/Blog.html); you should update your bookmarks. While I think you can still view the pages at the old address, you won’t be able to post comments.

    If you find that you can’t post comments at the new address, please send me an email to let me know.

  14. Markus says:

    I just discovered that Carl Buel made a great life-reconstruction of a killer sperm whale: http://www.cetacea-evolution.org/main/

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